1. Field of the Invention
The invention relates to a device for connecting pipelines, in particular high pressure pipelines, which are subjected to changes in axial length and are laid in mine shafts, for example.
2. Description of Related Art
Lines of this type are also called “shaft lines”. Shaft lines are not only used in hard coal mining in Germany, but also in hard coal mining in foreign countries; these pipelines have to convey fluids over many hundred meters to the respective underground mining operation. In this respect, there is often a problem regarding the linear extension of such installed shaft lines. Such a linear extension can be compensated by the use of hoses which are installed approximately every 100 m, or by the use of known expansion spirals which can compensate for a linear extension of from 40 to 50 mm per hundred meters.
If shaft lines with relatively large diameters and high pressures are used, the extension problem becomes even more complicated, since with thick-walled pipes, small spiral diameters cannot be bent and there are no hoses for pressure ranges of more than 400 bars to enable a flexible element to be laid in the shaft line.
Therefore, the object of the invention is to provide a device for connecting pipelines which are subjected to changes in axial length, which device can also be used for very high pressures, has a simple construction and nevertheless can be dismantled for maintenance and cleaning purposes.